omnidirectional microphones

I need an omnidirectional microphone for a podcast. I have like 30 usd but I can stretch for more if I had to. Preferably if there are any great podcasting mics at bestbuy (not necessarily omnidirectional but good for podcasting because I have gift cards)

What do you intend to plug the microphone into?
What do you wish to record with the microphone? (describe the show)

I can tell by my Spidey Sense that you want to record a round-table with a bunch of people speaking. Perfectly valid, but please note that you will also be recording the room. The Big Kids do shows like that in a studio to eliminate this effect:

The room is a performer in your show.

And yes, we’re going to need a lot more information. Both Macs and Windows laptops come with built-in microphones. have you tried yours?